Research Horizons

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A new process for recycling carbon fiber could keep tons of waste out of landfills

Researchers have developed a technique for recycling a specific type of carbon fiber composite material. The image shows a piece of carbon fiber composite immersed in alcohol.

Researchers have developed a method to recycle nearly 100 percent of the materials in certain types of thermoset carbon fiber composites.

The new method involves soaking the composites in an alcohol solvent, which slowly dissolves the epoxy that binds and gives shape to the carbon fibers. Once dissolved, the carbon fibers and epoxy can be separated and reused.

“This method, we think, could have a lot of immediate industrial applications, with lots of economical and environment benefits,” said Kai Yu, a postdoctoral researcher in the George W. Woodruff School of Mechanical Engineering at Georgia Tech.

Carbon fiber — prized for its strength and light weight — is used widely in applications from aerospace to automobiles. Jerry Qi, a professor in the Woodruff School who leads a team of researchers affiliated with Georgia Tech’s Renewable Bioproducts Institute, said traditional carbon fiber composites have presented difficult challenges for recycling because the polymer matrix is usually crosslinked and the material can’t just be melted to reclaim the embedded carbon fibers.

The research team focused on carbon fiber that uses a special type of epoxy called vitrimer epoxy to give the composite component its shape. The new recycling process has the potential to put a dent in the thousands of tons of carbon fiber waste that is generated each year in the United States and Europe, Qi said.

The study, which was sponsored by the National Science Foundation, National Natural Science Foundation of China, Singapore A*Star Public Sector Fund, and the Singapore NRF-supported Digital Manufacturing and Design Centre (DManD), was published in the journal AdvancedFunctionalMaterials. — Josh Brown